add singleKVS wrapper

ecc_go/chaincode/singleKVS.go

@@ -0,0 +1,45 @@
+/*
+Copyright IBM Corp. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package chaincode
+
+import (
+	"fmt"
+
+	"github.com/hyperledger/fabric-chaincode-go/shim"
+	"github.com/hyperledger/fabric-private-chaincode/ecc/chaincode"
+)
+
+var SingleKey = "SingleKey"
+
+type SKVSWrapper struct {
+	*chaincode.EnclaveChaincode
+}
+
+type skvsStub struct {
+	shim.ChaincodeStubInterface
+}
+
+func (s *skvsStub) GetState(key string) ([]byte, error) {
+	fmt.Printf("Inside SKVS solution, GetState, key=%s\n", key)
+	return s.ChaincodeStubInterface.GetState(SingleKey)
+	// return s.ChaincodeStubInterface.GetState(key)
+}
+
+func (s *skvsStub) PutState(key string, value []byte) error {
+	fmt.Printf("Inside SKVS solution, PutState, key=%s, value=%x\n", key, value)
+	return s.ChaincodeStubInterface.PutState(SingleKey, value)
+	// return s.ChaincodeStubInterface.PutState(key, value)
+}
+
+func (s *SKVSWrapper) GetStub() shim.ChaincodeStubInterface {
+	// get the original stub
+	stub := s.GetStub()
+	fmt.Println("Inside SKVS solution, GetStub")
+	// create a new stub with the overridden GetState() function
+	skvsStub := &skvsStub{stub}
+	return skvsStub
+}

samples/chaincode/secret-keeper-go/main.go

@@ -25,11 +25,14 @@ func main() {
 	secretChaincode, _ := contractapi.NewChaincode(&chaincode.SecretKeeper{})
 	chaincode := fpc.NewPrivateChaincode(secretChaincode)
 
+	// single KVS
+	skvsChaincode := &fpc.SingleKVSWrapper{chaincode}
+
 	// start chaincode as a service
 	server := &shim.ChaincodeServer{
 		CCID:    ccid,
 		Address: addr,
-		CC:      chaincode,
+		CC:      skvsChaincode,
 		TLSProps: shim.TLSProperties{
 			Disabled: true, // just for testing good enough
 		},